需要使用spark抽样检测hive中某张表的数据是否满足数据标准数据标准包括数据类型、数据长度、数据精度、数据空值、缺省值请帮我写出具体代码
以下是使用Spark抽样检测Hive表数据是否满足数据标准的代码:
import org.apache.spark.sql.SparkSession
object DataStandardCheck {
def main(args: Array[String]): Unit = {
val spark = SparkSession.builder()
.appName("DataStandardCheck")
.enableHiveSupport()
.getOrCreate()
// 获取表名和抽样比例
val tableName = args(0)
val sampleRate = args(1).toDouble
// 读取Hive表数据
val df = spark.sql(s"SELECT * FROM $tableName")
// 检查数据类型和数据长度
val schema = df.schema
schema.foreach(field => {
val fieldName = field.name
val fieldType = field.dataType.typeName
val fieldLength = field.dataType.defaultSize
val fieldMaxLength = field.metadata.getLong("maxlength")
val fieldMinLength = field.metadata.getLong("minlength")
val sampleData = df.select(fieldName).sample(false, sampleRate).collect()
sampleData.foreach(row => {
val fieldValue = row(0)
if (fieldValue != null) {
// 判断数据类型是否正确
if (fieldType.toLowerCase.startsWith("decimal")) {
assert(fieldValue.isInstanceOf[java.math.BigDecimal],
s"Field $fieldName is not decimal type")
} else {
assert(fieldValue.getClass.getSimpleName.toLowerCase.startsWith(fieldType),
s"Field $fieldName is not $fieldType type")
}
// 判断数据长度是否正确
assert(fieldValue.toString.length <= fieldMaxLength,
s"Field $fieldName length is greater than $fieldMaxLength")
assert(fieldValue.toString.length >= fieldMinLength,
s"Field $fieldName length is less than $fieldMinLength")
}
})
})
// 检查数据精度
df.schema.filter(_.dataType.typeName.toLowerCase.startsWith("decimal")).foreach(field => {
val fieldName = field.name
val fieldPrecision = field.dataType.asInstanceOf[org.apache.spark.sql.types.DecimalType].precision
val fieldScale = field.dataType.asInstanceOf[org.apache.spark.sql.types.DecimalType].scale
val sampleData = df.select(fieldName).sample(false, sampleRate).collect()
sampleData.foreach(row => {
val fieldValue = row(0)
if (fieldValue != null) {
val decimalValue = fieldValue.asInstanceOf[java.math.BigDecimal]
assert(decimalValue.precision() <= fieldPrecision,
s"Field $fieldName precision is greater than $fieldPrecision")
assert(decimalValue.scale() <= fieldScale,
s"Field $fieldName scale is greater than $fieldScale")
}
})
})
// 检查数据空值和缺省值
df.schema.foreach(field => {
val fieldName = field.name
val sampleData = df.select(fieldName).sample(false, sampleRate).collect()
val nullCount = sampleData.filter(row => row(0) == null).length
val defaultValue = field.metadata.getString("default")
val defaultCount = sampleData.filter(row => row(0) != null && row(0).toString == defaultValue).length
assert(nullCount == 0, s"Field $fieldName contains null value")
assert(defaultCount == 0, s"Field $fieldName contains default value $defaultValue")
})
// 输出结果
println("Data standard check passed!")
}
}
在使用时,需要传入Hive表名和抽样比例两个参数,例如:
spark-submit --class DataStandardCheck --master yarn --deploy-mode client --executor-memory 2G --num-executors 10 data_standard_check.jar my_table 0.1
其中,my_table是要检查的Hive表名,0.1是抽样比例(即从表中随机抽取10%的数据进行检查)。如果检查通过,程序会输出Data standard check passed!。如果检查不通过,程序会抛出异常并输出错误信息
原文地址: https://www.cveoy.top/t/topic/ge2r 著作权归作者所有。请勿转载和采集!